U.S. patent application number 13/509742 was filed with the patent office on 2012-12-13 for air conditioning compressor for a vehicle and vehicle.
This patent application is currently assigned to ROBERT BOSCH GMBH. Invention is credited to Bjoern Noack.
Application Number | 20120315170 13/509742 |
Document ID | / |
Family ID | 43414927 |
Filed Date | 2012-12-13 |
United States Patent
Application |
20120315170 |
Kind Code |
A1 |
Noack; Bjoern |
December 13, 2012 |
AIR CONDITIONING COMPRESSOR FOR A VEHICLE AND VEHICLE
Abstract
The invention relates to an air conditioning compressor (1) for
a vehicle (24), in particular a motor vehicle (25), having a
compression chamber (18) having an inlet (7) for a cooling medium
to be compressed and an outlet (8) for the compressed cooling
medium, wherein a wall of the compression chamber (18) is formed at
least in sections by a translationally displaceable piston (3).
According to the invention, the end of the piston (3) facing away
from the compression chamber forms at least one wall region of a
control pressure chamber (19). The invention further relates to a
vehicle having an air conditioning apparatus.
Inventors: |
Noack; Bjoern; (Bangalore,
IN) |
Assignee: |
ROBERT BOSCH GMBH
Stuttgart
DE
|
Family ID: |
43414927 |
Appl. No.: |
13/509742 |
Filed: |
September 21, 2010 |
PCT Filed: |
September 21, 2010 |
PCT NO: |
PCT/EP10/63859 |
371 Date: |
August 17, 2012 |
Current U.S.
Class: |
417/440 ;
417/437 |
Current CPC
Class: |
F04B 35/04 20130101;
F04B 49/002 20130101 |
Class at
Publication: |
417/440 ;
417/437 |
International
Class: |
F04B 41/00 20060101
F04B041/00; F04B 37/00 20060101 F04B037/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2009 |
DE |
10 2009 046 649.5 |
Claims
1. An air-conditioning compressor (1) for a vehicle (24), having a
compression chamber (18) which has an inlet (7) for a cooling
medium to be compressed and an outlet (8) for the compressed
cooling medium, wherein a wall of the compression chamber (18) is
formed at least in regions by a piston (3) which is displaceable in
a translatory fashion, characterized in that the piston (3) forms,
at an end facing away from the compression chamber, at least one
wall region of a control pressure chamber (19).
2. The air-conditioning compressor as claimed in claim 1,
characterized in that at least one of the inlet (7) and the outlet
(9) is formed at an end region (6), which is remote from the piston
(3), of the compression chamber (18).
3. The air-conditioning compressor as claimed in claim 1,
characterized in that at least one of the inlet (7) and the outlet
(8) has in each case one check valve (9, 10).
4. The air-conditioning compressor as claimed in claim 1,
characterized in that the piston (3) has at least none restoring
spring (20).
5. The air-conditioning compressor as claimed in claim 4,
characterized in that the restoring spring (20) is formed as a
helical spring (21) and arranged in the compression chamber
(18).
6. The air-conditioning compressor as claimed in claim 1,
characterized in that the control pressure chamber (19) is
incorporated into a hydraulic circuit (29).
7. The air-conditioning compressor as claimed in claim 6,
characterized in that the control pressure chamber (19) has a
high-pressure port (12) and a low-pressure port (13) for the
hydraulic circuit (29).
8. The air-conditioning compressor as claimed in claim 1,
characterized in that at least one of the low-pressure and the
high-pressure port (12, 13) has in each case one switchable valve
(14, 15).
9. A vehicle (24), having a drive device (26) and having an
air-conditioning device (31) which has an air-conditioning
compressor (1) according to claim 1.
10. The vehicle as claimed in claim 9, characterized in that the
control pressure chamber (19) is incorporated into a hydraulic
circuit (29) of the drive device (26).
11. The air-conditioning compressor as claimed in claim 1,
characterized in that the inlet (7) and the outlet (9) are formed
at an end region (6), which is remote from the piston (3), of the
compression chamber (18).
12. The air-conditioning compressor as claimed in claim 1,
characterized in that the inlet (7) and the outlet (8) have in each
case one check valve (9, 10).
13. The air-conditioning compressor as claimed in claim 1,
characterized in that the low-pressure and the high-pressure port
(12, 13) have in each case one switchable valve (14, 15).
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to an air-conditioning compressor for
a vehicle, in particular motor vehicle, having a compression
chamber which has an inlet for a cooling medium to be compressed
and an outlet for the compressed cooling medium, wherein a wall of
the compression chamber is formed at least in regions by a piston
which is displaceable in a translatory fashion.
[0002] The invention also relates to a vehicle, in particular motor
vehicle, having a drive device and having an air-conditioning
device which has an air-conditioning compressor.
[0003] Air-conditioning compressors and vehicles of the type in
question here are known from the prior art. To increase comfort in
vehicles, in particular with regard to the vehicle interior
temperature, it is known to provide air-conditioning devices which
serve for cooling the interior. For this purpose, air-conditioning
devices of said type have at least one air-conditioning compressor
which serves for the compression, which permits the air
conditioning, of a gaseous and/or vaporous refrigerant in a circuit
of the air-conditioning device. Here, air-conditioning compressors
are known which are based on the principle of a piston pump and
which, for this purpose, have a piston which is displaceable in a
translatory fashion and which serves for compressing a gaseous
and/or vaporous cooling medium situated in a compression chamber.
Here, the piston forms at least one wall region of the compression
chamber, such that as a result of a displacement of the piston, the
volume of the compression chamber is reduced, and the cooling
medium situated therein is compressed.
[0004] Known air-conditioning compressors are designed so as to be
mechanically driven by a crankshaft of an internal combustion
engine via a belt or chain drive. In this way, however, energy is
extracted from the drive device of a vehicle of said type, which
energy is no longer available for providing propulsion and also
becomes noticeable in terms of pollutant emissions (CO.sub.2
emissions).
SUMMARY OF THE INVENTION
[0005] The air-conditioning compressor according to the invention
is driven in such a way as not to reduce the power of a drive
device, and takes up a smaller amount of installation space than
known air-conditioning compressors. Accordingly, the
air-conditioning compressor is designed such that the piston forms,
at its end facing away from the compression chamber, at least one
wall region of a control pressure chamber. An air-conditioning
compressor is thus provided which has an axially displaceable
piston which interacts on one side, or with one end, with the
compression chamber and on the other side, or with the other end,
with the control pressure chamber. Here, as a result of the
pressure difference between the control pressure chamber and
compression chamber, the piston is displaced axially. The pressure
in the control pressure chamber can, as the name suggests, be
controlled, such that a compression process in the compression
chamber can be adjusted by increasing and decreasing the pressure
in the control pressure chamber. By increasing the pressure in the
control chamber, the piston is moved into the compression chamber,
and the volume of the compression chamber is reduced. By reducing
the pressure in the control pressure chamber, the piston is moved
out of the compression chamber, such that there is a follow-up
flow, and possibly suction, of cooling medium into the compression
chamber. The air-conditioning compressor according to the invention
is thus driven not mechanically but rather preferably
hydraulically. Here, the air-conditioning compressor may be
connected to an existing hydraulic system. The advantageous
air-conditioning compressor thus does not extract any energy
required for drive/propulsion from a drive device of a motor
vehicle.
[0006] It is advantageous for the inlet and/or the outlet of the
compression chamber to be arranged or formed at an end region,
which is remote from the piston, of the compression chamber. In
this way, it is ensured that the greatest possible volume of the
compression chamber can be utilized for conveying and compressing
cooling medium. In the simplest case, the inlet and/or the outlet
are formed as a bore/as bores in a housing which forms the
compression chamber.
[0007] It is preferable for the inlet and/or the outlet to be
assigned in each case one check valve. Here, the check valves are
designed and/or arranged such that, when there is an elevated
pressure in the compression chamber, the check valve assigned to
the inlet closes and the check valve assigned to the outlet opens,
such that cooling medium which has been compressed in the
compression chamber is expelled from the compression chamber at
high pressure when the piston is displaced into the compression
chamber. If, owing to there being a relatively low pressure in the
control pressure chamber, the piston moves in the opposite
direction, the check valve assigned to the outlet thus closes the
previously opened-up throughflow cross section and the check valve
assigned to the inlet opens up a throughflow cross section, such
that a follow-up flow of gaseous and/or vaporous cooling medium
into the compression chamber can take place. The check valves thus
ensure a pressure build-up in the compression chamber and a
separation between a high-pressure portion and a low-pressure
portion of a cooling circuit which conducts the cooling medium.
[0008] The piston is expediently assigned at least one restoring
spring, wherein here, the restoring action is to be understood to
mean the displacement of the piston out of the compression chamber.
In other words, the restoring spring serves to increase the volume
of the compression chamber by displacing the piston. This has the
advantage that the (negative) pressure to be set in the control
pressure chamber can be reduced in order to displace the piston in
the direction of the control pressure chamber. The restoring spring
permanently ensures reliable operation of the air-conditioning
compressor in that it exerts a spring force on the piston in the
direction of the control pressure chamber.
[0009] It is furthermore provided that the restoring spring is for
this purpose formed as a helical spring and arranged in the
compression chamber. The restoring spring thus acts as a
compression spring and is situated, possibly in a preloaded state,
between that end side of the piston which points toward the
compression chamber and a housing wall, which faces said end side
of the piston, of the compression chamber.
[0010] It is furthermore provided that the control pressure chamber
can be incorporated into a hydraulic circuit, in particular of a
drive device of a motor vehicle. For this purpose, the control
pressure chamber has corresponding ports which permit simple
incorporation into a hydraulic circuit of said type. It is
expedient for the material and material thickness of the housing
which forms the control pressure chamber to also be selected in
accordance with the high pressure requirements. This leads inter
alia to the control pressure chamber being formed as a hydraulic
chamber and the air-conditioning compressor being designed as a
hydraulically controlled air-conditioning compressor.
[0011] The control pressure chamber preferably has, for this
purpose, a high-pressure port and a low-pressure port for the
hydraulic circuit. Through the high-pressure port, hydraulic fluid
is conducted into the control pressure chamber such that the piston
is displaced into the compression chamber. For this purpose, a
pressure must expediently prevail at the high-pressure port which
is adequate to effect a displacement of the piston for compressing
the gaseous and/or vaporous cooling medium situated in the
compression chamber.
[0012] It is finally provided that the low-pressure and/or the
high-pressure port is assigned in each case one switchable valve.
In this way, it is possible in a simple manner to adjust not only
the working frequency of the air-conditioning compressor but also
the compression pressure acting in the compression chamber. By
opening the switchable valve assigned to the high-pressure port,
hydraulic fluid flows at high pressure into the control pressure
chamber. Here, the low-pressure valve is expediently closed. As a
result of the high pressure of the hydraulic fluid, the piston is
displaced into the compression chamber, and the cooling medium
situated therein is compressed. At the latest when the pressure in
the compression chamber corresponds to the pressure acting on the
piston in the control chamber--that is to say including the spring
force of the restoring spring--the valve assigned to the
high-pressure port is closed and the valve assigned to the low
pressure is opened, such that the hydraulic fluid flows out of the
control pressure chamber and the piston is restored as a result of
the loss of pressure in the control pressure chamber.
[0013] The vehicle according to the invention is characterized by
an air-conditioning compressor as described above. The
air-conditioning compressor is expediently incorporated into a
hydraulic circuit of the drive device, wherein it is advantageously
the case that the low-pressure port is connected to a low-pressure
portion of the hydraulic circuit and the high-pressure port is
connected to a high-pressure portion of the hydraulic circuit.
Through corresponding actuation of the switchable valves, it is now
possible for the cooling power of the air-conditioning device to be
controlled or regulated in a simple manner. Since a mechanical
drive of the air-conditioning compressor is dispensed with, no
energy required for propulsion is extracted from the drive device,
such that firstly the power of the drive device can be used
entirely for propulsion, and secondly pollutant emissions are
reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention shall be explained in more detail below on the
basis of the drawing, in which:
[0015] FIG. 1 shows an air-conditioning compressor in a simplified
sectional illustration, and
[0016] FIG. 2 shows a vehicle having an air-conditioning
device.
DETAILED DESCRIPTION
[0017] FIG. 1 shows, in a simplified illustration, a longitudinal
section through an air-conditioning compressor 1 for an
air-conditioning device in particular of a vehicle or motor
vehicle. The air-conditioning compressor 1 has a housing 2 which is
preferably of at least substantially circular cylindrical form. A
piston 3 is arranged in the housing 2 so as to be displaceable
axially--that is to say in the direction of its longitudinal
axis--in a translatory fashion. At its outer lateral surface, the
piston 3 has arranged thereon two seal elements 4 in the form of
O-rings 5 which sealingly close off the gap between the piston 3
and the inner side of the housing 2. At the same time, the seal
elements 4 may also serve for guiding the piston 3 in the housing
2. For guidance, however, it is expedient for further means (not
illustrated here) to be provided, for example in the form of guide
ridges and/or grooves, which serve in particular for minimizing
friction during the displacement of the piston 3 in the housing 2
and prevent the piston 3 from tilting and becoming jammed in the
housing 2.
[0018] The housing 2 of the air-conditioning compressor 1
furthermore has, in a first region 6, an inlet 7 and an outlet 8
which are formed in each case in the casing wall of the housing 2.
In the present case, the inlet 7 and the outlet 8 are aligned
substantially radially with respect to the housing 2. The inlet 7
has a first check valve 9 and the outlet 8 has a second check valve
10. The design and function of check valves is generally known,
such that the exact design of the check valves 9 and 10 shall not
be discussed in any more detail here.
[0019] At its end region 11 situated opposite the end region 6, the
housing 2 of the air-conditioning compressor 1 has a high-pressure
port 12 and a low-pressure port 13, which in the present case are
likewise formed in the casing wall of the housing 2. Here, the
high-pressure port 12 and the low-pressure port 13 are assigned in
each case one switchable valve 14 and 15 respectively. By means of
the ports 12 and 13, the air-conditioning compressor 1 can be
incorporated into the hydraulic circuit of a drive device of the
abovementioned motor vehicle. By means of the switchable valves 14
and 15, it is possible at the respective port 12, 13 for a
corresponding throughflow cross section to be closed or opened up.
The throughflow cross sections can possibly be adjusted in a
continuously variable fashion. The check valves 9, 10 and/or the
valves 14, 15 may in each case, at least in regions, be formed
integrally with the housing 2 or as separate attachment parts.
[0020] The piston 3 which is displaceably mounted in the housing 2,
and which is sealed off with respect to the inner wall of the
housing 2 by means of the sealing elements 4, divides the housing 2
into two chambers 16 and 17. The chamber on the side which has the
inlet 7 and the outlet 8 forms a compression chamber 18 for a
cooling medium of the air-conditioning device, which has the
air-conditioning compressor 1, of the motor vehicle. The chamber 17
which is situated on the opposite side of the piston 3 forms,
together with the piston, a control pressure chamber 19 which,
through the switching of the valves 14 and 15, substantially
controls the movement of the piston 3.
[0021] In the compression chamber 18 there is advantageously
arranged a restoring spring 20 formed in the present case as a
helical spring 21. Here, the restoring spring 20 interacts with the
free end side of the piston 3 and with the closed end side, which
faces the piston, of the housing 2 in the end region 6. The
restoring spring 20 is possibly arranged between the piston 3 and
the housing 2 with a preload, such that it always exerts a spring
force on the piston 3 in the direction of the control pressure
chamber 19. In order that the piston 3 does not enter completely
into the control pressure chamber 19, stops are expediently
provided in this case on the housing inner wall, which stops
prevent the piston 3 from protruding too far into the control
pressure chamber 19. The control pressure chamber 19 and the
compression chamber 18 are thus formed in each case by the walls of
the housing 2 and by in each case one free end side of the piston
3.
[0022] The function of the air-conditioning compressor 1 shall be
explained below: A gaseous and/or vaporous cooling medium of the
cooling circuit of the air-conditioning device is supplied to the
inlet 7. The check valves 9 and 10 ensure that the cooling medium
to be compressed can duly flow into the compression chamber 18 but
cannot flow out of said compression chamber again for as long as
the pressure in the compression chamber does not exceed a critical
pressure. For a compression process, the valve 14 is firstly opened
such that hydraulic fluid flows out of the hydraulic circuit of the
drive device into the control pressure chamber 19, while the valve
15 is closed. In this way, a pressure builds up in the control
pressure chamber 19, which pressure serves to move the piston 3 in
the direction of the compression chamber 16 or in the direction of
the end region 6, as indicated by an arrow 22. Here, the restoring
spring 20 is stressed and the gaseous and/or vaporous cooling
medium situated in the compression chamber 16 is compressed, with
the pressure in the compression chamber 18 being increased.
[0023] The remaining liquid phase is forced toward the check valve
10 of the outlet 8, as a result of which said check valve opens
when the critical pressure is reached, and the now liquid,
compressed cooling medium is conveyed or pushed through the outlet
8 into the cooling circuit at least for as long as the pressure in
the control pressure chamber is higher than the pressure in the
compression chamber 18. At the latest when pressure equalization
between the compression chamber 18 and the control pressure chamber
19 has taken place, the valve 14 of the high-pressure port 12 is
closed and the valve 15 of the low-pressure port 13 is opened. As a
result, the hydraulic fluid in the control pressure chamber 19
expands and flows through the valve 15 and the low-pressure port 13
back into the hydraulic circuit of the drive device. The restoring
spring 20 and the pressure difference which now prevails between
the control pressure chamber 19 and the compression chamber 18
serve to displace the piston 3 back, as indicated by an arrow 23,
into its initial position. Here, the coolant remaining in the
compression chamber 18 evaporates again, and as a result of the
suction action generated, additional gaseous and/or vaporous
cooling medium is sucked into the compression chamber 18 via the
check valve 9, while the check valve 10 is again closed. Here, the
above-described process starts to repeat. It is possible here for
the speed of the piston 3, and the movement travel of the piston 3,
to be manipulated through corresponding adjustment of the valves 14
and 15.
[0024] FIG. 2 shows a simplified illustration of an advantageous
exemplary embodiment of a vehicle 24 which is in the form of a
motor vehicle 25 and which, for this purpose, comprises a drive
device 26 which comprises an internal combustion engine and/or one
or more electric machines. The drive device 26 is assigned a
hydraulic unit 27 which has inter alia means for generating a
pressure for a liquid hydraulic medium. The hydraulic unit is
connected via a first hydraulic circuit 28 to components of the
drive device 26 and via a second hydraulic circuit 29 to the
above-described air-conditioning compressor 1. Here, a
high-pressure portion of the hydraulic circuit 29 is connected to
the high-pressure port 12 of the control pressure chamber 19 and a
low-pressure portion of the hydraulic circuit 29 is connected to
the low-pressure port 13. The compression chamber 18 is
incorporated, by means of its inlet 7 and its outlet 8, into a
cooling circuit 30 of an air-conditioning device 31, and is thus a
constituent part of the air-conditioning device 31. Also
incorporated into the cooling circuit 30 is a condenser 32 through
which ambient air flows, if appropriate with the aid of a fan 33,
as indicated by arrows 34. The air-conditioning device 31
advantageously furthermore comprises--though these are not
illustrated here--a collecting tank for the cooling medium, a
temperature-regulated switch for the activation and deactivation of
the air-conditioning compressor 1, in particular in the form of a
two-position controller, a temperature sensor assigned to the
switch, an expansion valve and also an evaporator with a switchable
evaporator fan for imparting the cooling power.
[0025] Overall, the air-conditioning compressor 1 thus provides, in
a particularly simple manner, a facility for compressing the
cooling medium without the need for extracting power from a drive
device 26 of the motor vehicle 25. Furthermore, the present
air-conditioning compressor 1 is of particularly compact and cheap
design. Furthermore, air conditioning can easily be provided even
when the engine is at a standstill, which in particular in modern
hybrid drive concepts which, as drive components, have not only a
classic internal combustion engine, such as a spark-ignition or
diesel engine, but also one or more electric machines.
[0026] To prevent contamination between the hydraulic fluid and the
refrigeration medium in the air-conditioning compressor 1, an
"atmospheric intermediate part" is provided, in a further exemplary
embodiment not illustrated here, between the compression chamber 18
and the control pressure chamber 19. It is thus possible, for
example, for one or more diaphragms to be provided in the housing 2
for the purpose of separating the various media. It is also
conceivable for the compression chamber 18 and the control pressure
chamber 19 to be provided in different, substantially mutually
separate housing parts, with a component piston being displaceably
mounted in each of the housing parts, and the component pistons in
turn being connected to one another via a corresponding
mechanism.
* * * * *